MP3 Watermarking Embraced By Music Industry
The next generation of digital audio devices, available by Christmas, will incorporate a new anti-piracy system, the latest step agreed upon by the 120 companies participating in the Secure Digital Music Initiative. SDMI announced its choice of a "watermarking" technology last Monday (Aug. 9).
Audio watermarks are actual sound signals hidden in music. A piece of hardware, such as a digital audio player, can read the signals--which are inaudible to the human ear--and identify the creator of the music, where the file came from (such as a Web site or CD), who obtained it, and how often it may be played. Music companies intend to use watermarking to prevent unlimited copying of music, which they fear will drastically cut their revenues.
SDMI screened several watermarking technologies, but the challenge was to find one that didn't distort the music and could withstand everything that can possibly be done to a music file, says Talal Shamoon, Chairman of the Screening Group at SDMI. A successful watermark must be readable even if the music is sped up, slowed down, compressed, manipulated with studio effects and voiceovers, or converted to analog sound and back.
SDMI chose a watermarking system developed by ARIS Technologies, Inc., a privately held company in Cambridge, Massachusetts. The technology has also been chosen for DVD audio by the 4C Entity, comprised of IBM, Intel, Matsushita Electric and Toshiba. ARIS will earn licensing fees from these companies, as well as from music companies which use the technology.
Watermarks will be introduced into the digital audio market in two phases. In the first phase, digital audio players will be able to play any type of music file, legal or illegal, including open formats such as MP3. In the meantime, music companies will begin inserting the watermarks into tracks.
When the second phase begins, music containing the watermark will trigger the player, notifying the user to upgrade player software so that the music can be played. At that point, only music from legitimately duplicated CDs and legal downloads will be playable. As for material created before watermarking was used, tracks ripped from CDs (such as those in a personal collection) will work, as will tracks downloaded from legal music distribution Web sites.
However, if tracks from watermarked music are converted to MP3 files (or other unprotected formats), they will not work. Many MP3 advocates fear that this will be the death knell for the format, which found a way to compress large-memory sound files while preserving better sound quality than had been possible before. There are now several alternatives to MP3 compression.
''New content, such as new releases, 'ripped' into something like MP3, won't be admitted by the player,'' says Shamoon.
The date of the second phase won't be decided until the SDMI meets in Florence, Italy on Sept. 1-2. And the exact details of how the trigger will work still need to be determined.
As for the level of security offered by ARIS watermarking, ARIS president David Leibowitz says that the strength of watermarking is that ''if you hack it, it destroys the sound quality.'' The technology is better than traditional encryption, he says, because encryption disappears when the material is in analog form. But given the human tendency to try and crack whatever is restricted, he admits that ''there are ingenious people out there, so that will be a wait-and-see.''
Although Shamoon doesn't know exactly how the ARIS technology works because it's proprietary information, he says that SDMI examined ''the threat model, looking at who's going to attack and what resources they have. Pure cryptography isn't as strong as watermarking [for audio], because the message is hidden, and cryptography can't do that.''
Never miss a story
Get the news as it happens via Facebook, Twitter or our old-fashioned RSS feed
Follow @soundspike